Conventionally, sheet-shaped photosensitive materials are stacked on a packaging material, and this stack of photosensitive materials is packaged tightly so as to seal them using the barrier packaging material. Sideways tilted U-shaped protective sheets (backing cardboard sheets) are used as the packaging material for protecting the sheet-shaped photosensitive material, as for example in the Japanese Utility Model Public Disclosure No. Sho 61-4915 and in the Japanese Utility Model Application Laid Open No. 55-164642. Further, examples of using plastic trays as packaging materials used for thermal development type photosensitive material are those given in Japanese Patent Application Laid Open No. 2002-31875, Japanese Patent Application Laid Open No. 2002-59980, and in Japanese Patent Application Laid Open No. 2002-72415. Also, addition of paper strength enhancing agent and sizing agents have been disclosed in Japanese Patent Application Laid Open No. Hei 7-104432 as the methods of preventing the generation of paper dust from the backing cardboard sheets used in the sheet-shaped photosensitive materials. Furthermore, Japanese Patent Application Laid Open No. Hei 11-258733 and Japanese Patent Application Laid Open No. Sho 60-26004 disclose methods of preventing the generation of paper dust from the backing cardboard sheets by bonding foam sheets or plastic films on the surface of the backing cardboard sheets. In addition, U.S. Pat. No. 5,473,400 and U.S. Pat. No. 5,480,134 disclose methods in which thermal development type photosensitive material is placed in a plastic tray on top of which is provided a film packaging material having a lid made of moisture-proofing sheet that can be re-sealed.
Patent Document 1: Japanese Utility Model Public Disclosure No. Sho 61-4915 (Page 1 to Page 2, FIG. 1)
Patent Document 2: Japanese Utility Model Application Laid Open No. 55-164642 (Page 1 to Page 5, FIG. 1)
Patent Document 3: Japanese Patent Application Laid Open No. 2002-31875 (Page 1 to Page 13, FIG. 1)
Patent Document 4: Japanese Patent Application Laid Open No. 2002-59980 (Page 1 to Page 16, FIG. 1 to FIG. 9)
Patent Document 5: Japanese Patent Application Laid Open No. 2002-72415 (Page 1 to Page 15, FIG. 1 to FIG. 7)
Patent Document 6: Japanese Patent Application Laid Open No. Hei 7-104432 (Page 1 to Page 8, FIG. 1 to FIG. 2)
Patent Document 7: Japanese Patent Application Laid Open No. Hei 11-258733 (Page 1 to Page 4, FIG. 1 to FIG. 2)
Patent Document 8: Japanese Patent Application Laid Open No. Sho 60-26004 (Page 1 to Page 5, FIG. 1)
Patent Document 9: U.S. Patent Public Disclosure No. 5473400
Patent Document 10: U.S. Patent Public Disclosure No. 5480134
Among such conventional technologies, the status of stacking products of photosensitive materials becomes stable when a plastic tray is used as the packaging material. However, plastic trays become too bulky at the time of their disposal after use, and even their environmental load is high in the burning stage during disposal. In addition, at the time of re-sealing, since the adhesive agent remains on the plastic tray and cannot be removed, value as a recyclable material becomes low.
In addition, when using paper backing cardboard, although the processing during disposal is easy compared to plastic trays, in particular, it is not possible to prevent the generation of paper dust due to the rubbing between flap side surface of the backing cardboard and the photosensitive material. There was the problem that even if larger quantities of sizing agents or paper strength enhancing agents are included in order to prevent the generation of paper dust, it only increases the cost and not much effect can be expected.
The present invention was made in view of the above aspects and the purpose of the present invention is to provide a method of manufacture of photosensitive material packaging body and photosensitive packaging body that prevent the generation of paper dust and also make the disposal processing easy after use.